The present invention generally relates to coffee roasters, and more particularly to a coffee roaster that has multiple roasting stages.
A demand for coffee roasters for home use has been on the rise in response to growing number of devoted coffee drinkers who desire the flavor of freshly roasted coffee. These home coffee roasters typically have a heating element and a fan for directing hot air into a roasting chamber where the coffee beans are roasted as they are blown around by a hot air stream. The controls on these roasters typically include a variable timer that allows beans to be roasted at a constant temperature for a prescribed time. Coffee beans come in different densities and have varying moisture content. As a result, roasting coffee beans at a constant temperature for a prescribed time, as in conventional coffee roasters, do not always result in consistent and fully developed flavor that coffee enthusiasts desire.
There are coffee roasters that have more than one roasting stages, where coffee beans are roasted, for example, at one temperature for some time and at another temperature for a certain other time period. These roasters, however, do not have the means for maintaining the desired roasting temperature when the ambient temperature varies. Depending on the ambient temperature in which the roaster is operated, there could be a significant temperature variation in the roasting chamber from the desired temperature. For example, some users are known to place the coffee roaster outside the home during use, so as not to have smoke from the roaster fill the inside the house. In such a situation, the temperature inside the roasting chamber may not be at the desired temperatures, resulting in the beans being over or under roasted.
The present invention is directed to a roaster for roasting coffee beans, and includes a roasting chamber having a top and a bottom for holding coffee beans when the beans are being roasted, a cover seated on the top of the roasting chamber and a base on which the bottom of the roasting chamber is seated. A device is provided in the base for supplying airflow into the roasting chamber. A controller controls the airflow supplying device to generate a roasting temperature inside the roasting chamber that tracks a predetermined temperature curve. The temperature curve includes a first stage in which the roasting temperature is set to a first predetermined level for a first predetermined time period, and a second stage in which the roasting temperature is set to a second predetermined level that is higher than the first predetermined level. The second stage includes a plurality of stages including a current stage in which the roasting temperature is set to a current predetermined level for a current predetermined time period, and a subsequent stage in which the roasting temperature is set to a subsequent predetermined level that is higher than the current predetermined level for a subsequent predetermined time period.